This invention relates to a deceleration valve used in a vehicle emissions control system.
Deceleration valves are necessary in vehicle emissions control systems in order to eliminate engine backfiring and to reduce hydrocarbon emissions during vehicle declerations. These deceleration valves are responsive to an increase in engine manifold vacuum, thereby indicating a vehicle deceleration, to vent the vehicle air cleaner to the vehicle manifold vacuum. Of course, it is necessary in any valve design to provide an assembly which can be readily manufactured in substantial quantities at a relatively inexpensive cost. Accordingly, it is necessary to design a valve which, preferably, may be automatically assembled, and which has as few parts as possible.
Accordingly, the present invention proposes a valve having a valve assembly comprising an annular flexible member which is clamped between an upper and a lower diaphragm plate. The upper diaphragm plate includes a projecting portion which extends through the opening in the annular flexible member, and is provided with a groove which circumscribes the projecting portion. The lower diaphragm member includes a plurality of circumferentially spaced, axially extending, radially deflecting, resilient fingers which can be deflected radially when the valve is assembled, but snap into the groove in the projecting portion to therefor hold the two plates together when the valve is assembled. Of course, the inner periphery of the flexible member is clamped between the two plates, and the connection holds the entire assembly together. Furthermore, the projecting portion includes a coaxial aperture which receives a barbed pin, the barbs on the pin cooperating with the wall of the aperture to secure the pin to the diaphragm assembly. The pin carries a valve poppet, which is responsive to movement of the diaphragm to control communication between the air cleaner and the manifold vacuum.